Lucille is a new government official educated in medicine, sent to the development project from Central. She is a junior to Escha and Logy within the development team, and address them both with the "senpai" honorific. She is serious about her work, polite, and nice, but sometimes she makes big mistakes.

Lucille is an only child and comes from the rich Ernella family, who runs the medicine specialist Ernella Company. She usually gets along well with her parents, but since she was unable to find work in the places where the company has a strong influence, she asked to be assigned to a place as far from Central as possible.

She has been doing her best studying to become a doctor, but was left behind. Because of this, even if she wanted to become a doctor, she became a government official to make use of what she had learnt.

When she is not helping others, she studies the great medical treatment art revived from the premodern times. Lucille also collects figurines, and has collected very many.